Automatic pouring furnace



May 18, 1965 W. E. SHEARMAN Filed June 6. 1961 AUTOMATIC POURING FURNACE 6 Sheets-Sheet 1 INVEN TOR. W150 E JHFAHJMAN 14 TUBNEY y 18, 1965 w, E. SHEARMAN 3,184,226

AUTOMATIC POURING' FURNACE Filed June 6, 1961 6 Sheets-Sheet 2 1. INVENTOR,

Ilka: E SAa-"ARMAN ir razzvzy y 18, 1955 w. E. SHEARMAN 3,184,226

I AUTOMATIC POURING FURNACE Filed June 6, 1961 6 Sheets-Sheet 5 z9 EJRj 6 4' g gamzszmmm E JE-X TTOBNE'Y y 1965 w. E. SHEARMAN 3,184,226

AUTOMATIC POURING FURNACE Filed June {6, 1961 6 Sheets-Sheet 4 '7 ,lll '7 INVEN TOR. iii 4 E .fi'A/FAMAN ATTORNEY y 1955 w. E. SHEARMAN 3,184,226

AUTOMATIC POURING FURNACE Filed June 6, 1961 6 Sheets-Sheet 5 Q m Q \Q I III/II III I I l f: A I

L J E. 0% =1 Q 1 a, "3 w REG AIR SUPPLY INVEN TOR. W115? E SHEAR/MAN ATTOBNEY y 1955 w. E. SHEARMAN 3,184,226

AUTOMATIC POURING FURNACE Filed June 6, 1961 6 Sheets-Sheet 6 INVENTOR. Ignaz E SA/FAEAMN ATTORNEY United States Patent 3,184,226 AUTOMATIC PUURENG FURNAQE Wilbur E. Shearman, Yardley, Pan, assignor to Ajax Magnethermic orporation, Youngstown, Ohio, a corporation of Ohio Filed June 6, 1961, Ser. No. 115,221 Claims. (Cl. 266-38 My invention relates to the art of dispensing molten metal from a holding furnace, for example, discharging molten metal towards a mold, and relates more particularly to methods and apparatus for intermittently dispensing accurate amounts of molten metal from a vessel.

My invention particularly applies to methods and apparatus for periodically dispensing predetermined accurate amounts of molten metal from an automatic pouring furnace, sealed and under pressure, the molten metal being supplied to said pouring chamber from a supply chamber open to atmospheric pressure and adapted for periodic recharging.

My invention contemplates the use of separate supply and discharge chambers, the one operating as a supply chamber being connected to the pressure discharge chamher by a conduit, means disposed in the pressure chamber and adapted to be associated with said duct means and adapted to substantially close the duct during the application of periodic pressure to the sealed discharge chamber to largely prevent ejection of molten metal from the pressure chamber to the open chamber during the pressure cycle, thereby permitting much higher production rates than heretofore accomplished, and eliminating substan tial fluctuations in the level in the pressure chamber, thus achieving a greater accuracy of pour.

The improved means adapted to act to substantially restrict or allow free flow of molten metal flowing from one chamber to the other is preferably simple, composed of but few parts, requiring but slight maintenance and is readily adaptable for use in existing mechanisms.

It is among the objects of the present invention to provide for methods and means for charging a dispensing chamber independently of the successive discharge thereof by providing a duct means associated with said dispensing chamber, and means associated with said duct means to selectively open or substantially close said duct means.

It is a further object of my invention to achieve an independent charging of the supply chamber from the discharge of the molten metal from the dispensing chamber by providing a duct between said supply and dispensing chambers, said duct having means associated therewith for opening or substantially closing said duct.

It is a still further object of my invention to achieve the above described independence where the supply chamber is open to atmospheric pressure and adapted for pcriodic recharging and where the discharge chamber is sealed and under pressure.

Yet another object of my invention is to substantially shut off communication between said supply chamber and said dispensing chamber during the pressure cycle by providing means positioned between the said supply and dispensing chambers to substantially close the supply chamber during the said pressure cycle thereby preventing the ejection of molten metal from the dispensing pressure chamber to the open supply chamber during the application of pressure to the surface of the metal in the dispensing pressure chamber to cause the periodic discharge of accurate measured quantities of molten metal therefrom; the said means being operated essentially in step with the periodic pressure applied.

With the above and other objects of the invention in view, the invention consists in the novel methods, construction, and combination of various elements and parts, as set forth in the claims hereof, one embodiment of the 3,184,226 Patented May 18, 1965 same being illustrated in the accompanying drawings and described in the specification.

In the drawings:

FIG. 1 is a plan view of the combination supply and discharge chambers of my invention;

FIG. 2 is a sectional view of the combination furnace of my invention taken on lines 2-2 of FIG. 1, certain parts of the supply chamber being eliminated for the purpose of clarity;

FIG. 3 is a sectional view of the discharge chamber taken on lines 3-3 of FIG. 1;

FIG. 4 is a sectional plan view of the furnace taken along lines 4-4 of FIG. 2;

FIG, 5 is a fragmentary end assembly view of the discharge chamber, showing particularly the actuating mechanism for the valve gate, taken in the direction of the arrows of section line 55 of FIG. 2;

FIG. 6 is an end view of the valve duct positioned between the supply and discharge furnaces;

FIG. 7 is a plan view of the valve duct, taken along section 77 of FIG. 6;

FIG. 8 is a vertical sectional view of the valve duct, taken on lines 8-8 of FIG. 6;

FIG. 9 is a plan view of the slidable valve gate, and

FIG. 10 is an end view of the slidable valve gate, taken on lines 1010 of FIG. 9; and

FIG. 11 is a diagramamtic view showing the electric circuit for the operation of the valve gate and the pressure cycle for the dispensing chamber.

Referring now to the drawings, in all of which like parts are designated by like reference characters, and referring particularly to the embodiment disclosed in FIGS. 1 and 2, there is provided a furnace generally indicated at 1 which comprises two chambers or vessels or containers, namely a supply chamber 11 for molten metal and a discharge chamber 12. Each of the chambers 11 and 12 preferably has separate, independent heating means such as electro-magnetic induction units 14 and 15, respectively, of the usually termed submerged resistor type. End Walls 17 and 18 of the supply and discharge chambers 11 and 12, respectively, combine to form an eflective partition between said chambers. The end wall 17 of the supply chamber 11 has a tapered opening 46 therein. The abutting end wall 18 of the discharge chamber has a similar tapered opening 39, which, when the chambers 11 and 12 are in their assembled operative position, is aligned with the opening 46 to form a passage or conduit 40 affording intercommunication between the supply chamber 11 and the discharge chamber 12. Mounted in opening 39 is a duct 41 which has a loosely fitted valve gate or slide 45 adapted to be vertically reciprocated therethrough to control flow of molten metal between the supply chamber 11 and the discharge chamber 12, in a manner to be more fully explained hereinbelow.

The supply chamber 11 and discharge chamber 12 are provided on the interior thereof with refractory lining mat rial 4. Located exteriorly of the refractory lining 4 for each chamber is an insulating lining 5. The refractory lining 4 and insulation 5 in each chamber are enclosed by a metallic shell or casing 66 which forms the exterior wall of the two chambers. The metallic shell surrounding the discharge chamber 12, in conjunction with a sealed cover 29 therefor, provides for air or gas seal in the discharge chamber 12 whereby, during operation, a controlled discharge of metal therefrom by means of a varied or differently timed pressure applied to the level of the molten metal, can be elfected. The supply chamber 11 is provided with cover means 13 to reduce heat loss and cover 13 extends only partially over the top opening in the supply chamber 11, thus affording an opening 8 for charging supply chamber 11. Although the manner in which the supplychamber 11 ischarged forms no essential part" of this invention, it will be noted that the charge may be introduced as desired, independently of the operation of the discharging chamber. Cover13 for the supply or charging chamber 11, is preferably provided with'cleaning ports 13' through which appropriate cleaning tools can beinserted intothe-channels in: the induction heaters 14. a

The supply. and discharge chambers 11 and 12, and particularly the end walls 17 and 18 thereof, are secured by means of flanges integral therewith extending later-ally outwardly from the side and bottom walls of the cham;' bars 11 and 12 inthe area where the end walls 17 and-18 similarly held rigidly together by means-of bolt means End walls '17 and 18 are secured together at their top portions by means of a flat bridging plate 20'which is secured by bolt means 22, 22 to T-shaped inserts 23 and 24, which are embedded in the upper surfaces of the end walls 17 and 18, as shown. Lid flanges 26 and 27, which form part of the shell or casing 6, are bolted to the'outer ends of inserts. 23 and 24, as shown at 29 and 30, thus securing chambers 11 and 12 together at their top por tions.

It will thus be seen that chambers 11 and 12arerigidly secured together at the juncture of the bottom, side andtop walls, thus forming, -in effect, a unitary furnace 'having supply and discharge chambers.

Positioned between the end walls 17 and 18 is a sealing 1 means, such as, e.g., a-gasket 32, which is disposed between the, end walls 17 and18-as shown in FIG. 2. The

said gasket 32 is also interposed between the flanges 33 a and 34, openings being provided in the gasket 32 to align with openings in the flanges to receive the bolt and nut means 38,. t-elescoped. therethrough. Thegasket32, as shown, extends outwardly beyond the side casing walls, as shown in FIG. 4, and, in a similar" fashion; is. firmly securely gripped by the flanges 33-34'-and bolted thereto.

The gasket -32 is centrally'apertured as at 36, the said opening being :at least equal in size to and aligned with the.

communicating open ends of the duct 40 and the tapered opening 46.

The gasket 32 is preferably provided to ensure the seal of the dispensing chamber 12 and seals off the pressurized.

gas or air which might permeate through the refractory lining or insulation material. It thus assists in the maintenance of a determinate pressure in the dispensing chamber 12 during the pressure cycle.

In FIG. 3, the discharge or pouring chamber 12 is.

shown in greater detail. The chamber, as illustrated, is heated by an induction unit 15 and molten metal contained therein is adapted to be dispensed therefrom through a discharge tube 53. The discharge tube 53, as

shown, is angularly' disposed relative to and communii discharged from the said discharge chamber through the tube 53 by means of the application of momentary air or gas pressure delivered from a source, such as shown at 59 through a chamber 60 and an opening 63, in an end wall of the chamber, the pressure being deliveredt-o the space 12a above the molten metal in the pouring chamber 12. Solenoid valves 60, FIG. 11, control the flow of pressurized air through line 59. The amount of air pressure applied, or the time period during which the pressure is applied, depends upon the level. of molten metal. The specific manner in which the level of the molten metal is ascertained and the amount of pressure or the duration of application thereof is accomplished, does not form a part of this invention, and therefore a detailed description thereof is deemed unnecessary. It should be sufiicient to say, for the purposes of this invent-ion, that the amount of pressure or duration of application thereof, are related to the level of the molten metal in the pouring chamber, as determined by float means 110. Float means 110 is provided withan upright rod 111 which is part of a differential transformer which may be connected in circuit to an adjuster to reset a control mechanism for the pressure source, which may be a' compressor operating through solenoid valve 60, asshown in US. Letters Patent No.

2,937,789 to Mario Tama, issued May 24, 1960. It will throttle the flow through the tube.

Referring now more particularly to FIGS.,; 6-8, the

,duct 41 has a relatively smaller dimensioned end which is generally rectangular in shape, comprising a bottom wall 71, top wall 73, and side walls 72-72. Top wall 73, is tapered upwardly from the relatively smaller end of'the duct and the side Walls 7272 are tapered outwardly away from the end 70,'terminating in a relatively larger dimensioned end 74, also preferably rectangular in cross section, as noted in' FIG. 6. A gate-receiving aperture or slot 75 in the duct is provided adjacent the small end 70 of duct 41. By providing the, gatereceiving slot in the relatively smaller dimensioned portion of duct-.41, a relatively lesser, amount of vertical movement is required of valve gate 45 in order'to open or closethe duct 41. The duct 41 is preferably constructed from silicon nitride bonded silicon carbide, which has proven to be highly durable in furnaces maintained athigh temperature such as, e;g., aluminum melt furnaces.

The valve gate 45, shown in-FIGS. 9 and 10, 'ispreferably rectangular in cross-section and apertures 82 are provided in the upper portion 81 wherefor the gate 45 may be secured by pin means-to a vertically reciprocable cates with the inside of the discharge chamber 12 through a lateral recess or pocket 54 provided in the refractory lining of a side wall 55 ofthe chamber 12. As noted" above, the pouring chamber "12 is sealed and under pressure, the sealing being provided by a cover 29 and a sealed.

closure means disposed on the topthereof, such as door or lid 29'. Referring to FIGS. 1 and 2, door or lid' 29' has connected thereto, at the upper portion thereof, a pair of arms 6161 adapted to be secured asby clamping means 62 to means disposed on the upper casing to seal the chamber. A gasket (not shown) is employed between the cover 29 and door 29 to afford a proper sealing therebetween.

When the door 29' is clamped and the chamber 12 thus maintained-in a sealed condition, molten metal may be gate actuating means.

It will be apparent, noting FIG; 2, that when the valve gate 45 is in its adjusted upward position, as shown in solid lines, the chambers Hand 12 openly communicate through the opening 46 and the aligned opening in duct 41. When the valve gate is in its lowermost, dotted line position, as shown in FIG. 2, communication between the supply chamber 11 and the, discharge chamber 12 is substantially shut ofli.

It should be noted that the valve gate 45 is loosely slidable within the opening 75 the duct. during the uprapid, a relatively tight' fitting relationship would result in relatively high impacting between the gate side and end walls and the walls of slot 75. Discharge pressure during the pressure cycle further assists the gate means in closing the passage between the chambers, the said pressure forcing the gate into intimate contact with the walls of the slot 75 on the supply side. It will be noted that in the form shown herein, the gate and slot have substantially flat mating surfaces.

Although the slot 75 and valve gate 45 are shown as rectangular in cross section, the slot 75 and the lower portion of the gate 45 may be of various form, as, for example, slightly tapered to facilitate alignment therebetween during the downward movement of the gate 45. If a tapered relationship is employed, the slot 75 is preferably still made to loosely accommodate the gate 45, for the reasons explained hereinbefore and the gate and slot are provided with mating surfaces.

The valve gate 45, similar to the duct 41, is preferably constructed of silicon nitride bonded silicon carbide.

Referring now to FIGS. 2, 5, and 11, the valve gate actuating means is shown in its operative assembly. Although it should be apparent that the valve gate 45 could be vertically reciprocated by any known means, an air cylinder is preferably employed for accomplishing the required vertical motion of the gate. Pressurized air enters the actuating device through an air conduit 51 into an air chamber 52. From the chamber 52, housing preferably a four-way solenoid valve 52, the pressurized air flows alternately through speed control valves 54, 54 through air conduits 55 and 56. The conduit 55 is connected to an air cylinder 58 which is located in the upper portion of the valve gate actuating device 50 and conduit 56 is connected to the cylinder 58 at a point near the bottom of cylinder 58. A reciprocating piston 57 is vertically slidable within cylinder 58 and is operatively connected to valve gate 45 through rod 65 and coupling 68, the coupling 68 being connected to the valve gate 45 by bolt means 69 inserted through openings 82 in the valve gate and aligned openings in coupling 68.

It will thus be seen that when the solenoid valve 52' is in the position shown in FIG. 11, pressurized air will flow through solenoid valve 52, speed control valve 54, and conduit 56, thus forcing piston 57 into its uppermost position. In this position, air will be exhausted through conduit 55, positioned at the upper end of the cylinder. When the solenoid valve 52' is actuated in a manner to be explained hereinbelow, pressurized air will then flow into the conduit 55 through speed control valve 54, forcing the piston 57 into its most downwardly adjusted position, the air below piston 57 being exhausted through the line 56.

Referring now to FIG. 11, showing the control circuit for the operation of the valve gate and the pressure cycle for discharge chamber 12:

The source of alternating current is shown at L1, L2. When the starting contact SC is closed, momentarily, either automatically or manually, by means (no shown), the solenoid 90 is energized, moving the solenoid valve 52' to a position wherein air, supplied to the solenoid valve from a source (not shown), flows through the said valve 52', the speed control valve 54 and the conduit 55 to the upper portion of cylinder 58, forcing the reciprocating piston 57 downwardly into its lowermost position and forces the associated valve gate 45 downwardly, thereby substantially closing the duct 41.

It will be noted that as the piston 57 is moved downwardly by the admission of air or gas pressure into the upper chamber of the cylinder, the collar 92 of the piston rod 91 is caused to actuate a limit switch LS which, as best shown in FIG. 5, has a guide roller g secured thereto which contacts the collar 92. Upon closure of the limit switch LS, the time cycle is initiated, by coil means 94, actuating the contact RL1. The control relay RL-1 energizes in turn a pour control relay, PCR, which in turn energizes a pair of solenoid valves 66, shown in FIG. 3, whereby pressurized air from a source or supply 59 will be introduced into the space 12a above the level of the molten metal in the chamber 12 through a chamber 60 secured to the furnace and communicating with a passage 63 in an end wall of the chamber 12. The pour control relay PCR, when energized, by-passes switch SC to maintain the solenoid energized, holding it in the position noted hereinafter.

After a predetermined time interval, as determined by the timer 95, the control relay RL2 is caused to open, deenergizing the pour control relay PCR which releases the valve regulated pressure on the molten metal in discharge chamber 12 and exhausts the air or gas therein through an exhaust valve means associated with the air chamber 66. The opening of the pour control relay PCR further deenergizes the solenoid 99, thus moving valve 52' to its FIG. 11 position wherein the pressurized air-flow is shown flowing through the speed control valve 54; and conduit 55 to the lower portion of cylinder 58, whereby the piston 57 is moved upwardly to its uppermost position, air in the upper chamber of the cylinder is exhausting through the line :55, thus completing the gate closing and pouring cycle.

While I have described the gate or slide means as actuated by the means described above and have described a piston operated cylinder in connection therewith, it will be understood that other means might be employed to reciprocate the improved gate or slide means of my invention and to achieve the sequence of operation described herein, and my invention is not to be limited to the particular actuating means shown and described.

The bottom surface of valve gate 45 preferably projects through the opening, through the bottom of the duct 4t when in its lowermost adjusted position, as shown in FIG. 2. Thus, any heavy suspended particles which may tend to accumulate in the lower portion of the opening 75 in the duct 4d are ejected into the bath and hence cannot accumulate under the bottom surface of the gate 45.

The relatively smaller end 10 of duct 41 extends sufliciently far into the pressure chamber 12 to assure that its temperature will be the same as the molten metal in the furnace. This equality of temperature prevents freezing and the location prevents side wall build-up from impairing the movement of the gate 45 in the slot 75 of the duct 41 during opening and closing.

The operation of my new furnace structure should be apparent from the above description thereof but will be described for purposes of clarity. Valve gate 45 is vertically reciprocated by pressurized air means, and is adapted to be reciprocated downwardly substantially closing the duct 41 immediately prior to the exertion of pressure on the metal in the discharge chamber 12. The gate valve is held in substantially closed position during the pressure cycle and is assisted in such closure by the pressure applied on the metal in the discharge chamber and opens the conduit between the supply and discharge chambers immediately subsequent to the release of pressure on the molten metal in the discharge chamber. Thus, the discharge chamber 12 is substantially shut off from the supply chamber 11 during the application of pressure on the molten metal in the discharge chamber, preventing a substantial iiow thereof into the supply chamber 11. The upward movement of the valve gate 45 immediately subsequent to the release of pressure on the molten metal in the chamber 12 ensures the flow of molten metal from the supply chamber 11 to the discharge chamber 12 until a subsequent cycle of operation is initiated.

It will be apparent to those skilled in the art that the novel principles of the invention disclosed herein will suggest other modifications and applications of the same. Accordingly the foregoing is intended by way of illustration of a preferred embodiment only and not as a limitation of the scope of the present invention except as set forth in the appended claims.

What I claim is:

1. A furnace comprising a pair of chambers arranged chamber is sealed and the other of said chambers is opened 7 side by, side adapted to contain molten chambers being a discharge chamber, an opening interconnecting said chambers affording a passage for molten metal to said discharge'chamber from the other of said chambers, means operable. for applying intermittent PIES. sure fromabove the level of molten" metal in said discharge chamber to intermittently discharge molten metal theremetal, .one of said,

, a s to atmospheric pressure and adapted for periodic recharging and whereinthe'control means operate said loosely fitted sliding valvemember in step with the application of periodic pressure on the metal in the discharge chamber from, a sliding valve member looselyifitted' and mounted Within said discharge chamber, control means adapted to reciprocate the said valve means with respect to said opening to selectivelyisubstantially prevent the fio'w of molten metal between said chambers during the application of said pressure, the said pressure applied to the metal in, the discharge cycle forcing the said valve meansinto contact with said passage surrounding the opening to assist in closing the said opening between the said chambers during the applicationof said pressure, the said valve meansbeing subsequently reciprocated by said control means to permit and the release of such pressure therefrom.

, 5. A, furnace comprising a pair of chambers arranged side by'side adapted to contain molten metal, one of said chambers being open to atmospheric pressure and adapted for periodic recharging, the other of said chambers being the how of molten metal through the said passage between 7 the chambers.

2. A furnace as claimed in claim 1 wherein the passage interconnecting said chambers is provided with a conduit conduit open between saidipressure 'cycles'.

portion projecting within the discharge chambensaid conduit portion having a transverse opening therein and said sliding valve member being loosely fitted and reciprocated through said transverse opening. 9

3. A furnace asclaimed in claim 1 wherein the said control means to reciprocate the said mounted means in said transverse opening to close the conduit passage reciprocates the said loosely fitted sliding valve member immediately prior to the application of pressure on the. molten metal in the discharge chamber tosubstantially' close the conduit passage and prevent the flow of molten metal between the chambers during the pressure cycle and said sliding valve means is withdrawn from said opening immediately after the close of said pressure'cycle to permit the flow of molten .metal through said conduit between pressure cycles. V

4. A furnace as claimed in claim 1 wherein the discharg 1 References Cited by theExaminer UNITED STATES PATENTS 2,816,334 -12/57 Edstrand 22-79 2,939,899 6/60 Edstrand et al. I 3,032,841 5/62 Sylvester 2Z69' 7 I FOREIGN PATENTS 907,368 .6/255 France. v 702,833 1 /54 Great Britain. 837,867 6/60 Great Britain. 292,862 11/ 53 Switzerland.

r OTHER REFERENCES" Modern Metals,,vol. VI, :Issue 1, pages 19-21, 'February 1960.

JOHN F. CAMPBELL, Primary Examiner. RAY K. WINDHA-M, MORRIS'WOLK, Examiners. 

1. A FURNACE COMPRISING A PAIR OF CHAMBERS ARRANGED SIDE BY SIDE ADAPTED TO CONTAIN MOLTEN METAL, ONE OF SAID CHAMBERS BEING A DISCHARGE CHAMBER, AN OPENING INTERCONNECTING SAID CHAMBERS AFFORDING A PASSAGE FOR MOLTEN METAL TO SAID DISCHARGE CHAMBER FROM THE OTHER OF SAID CHAMBERS, MEANS OPERABLE FOR APPLYING INTERMITTENT PRESSURE FROM ABOVE THE LEVEL OF MOLTEN METAL IN SAID DISCHARGE CHAMBER TO INTERMITTENTLY DISCHARGE MOLTEN METAL THEREFROM, A SLIDING VALVE MEMBER LOOSELY FITTED AND MOUNTED WITHIN SAID DISCHARGE CHAMBER, CONTROL MEANS ADAPTED TO RECIPROCATE THE SAID VALVE MEANS WITH RESPECT TO SAID OPENING TO SELECTIVELY SUBSTANTIALLY PREVENT THE FLOW OF MOLTEN METAL BETWEEN SAID CHAMBERS DURING THE APPLICATION OF SAID PRESSURE, THE SAID PRESSURE APPLIED TO THE METAL IN THE DISCHARGE CYCLE FORCING THE SAID VALVE MEANS INTO CONTACT WITH SAID PASSAGE SURROUNDING THE OPENING TO ASSIST IN CLOSING THE SAID OPENING BETWEEN THE SAID CHAMBERS DURING THE APPLICATION OF SAID PRESSURE, THE SAID VALVE MEANS BEING SUBSEQUENTLY RECIPROCATED BY SAID CONTROL MEANS TO PERMIT THE FLOW OF MOLTEN METAL THROUGH THE SAID PASSAGE BETWEEN THE CHAMBERS. 